(Museum of Natural History, University of Oregon, 1966-10) Emlong, Douglas
Intensive search by the author, in marine Oligocene formations of Oregon has resulted in the discovery of a
very interesting cetacean skeleton. This animal possesses so many distinctive features that it seems appropriate
to propose a new family, the Aetiocetidae for its reception.
Although this mammal possessed a functional dentition, and bears some resemblance to cetaceans belonging to families Agorophiidae, Patriocetidae, and Microzeuglodontidae, its total compliment of dissimilarities
from known cetaceans indicates that it is well differentiated from these families.
Many features appear to be definitely antecedent to those developed on members of the suborder Mysticeti.
If it were not for the presence of functional teeth on this mature specimen, this cetacean could easily be
placed in the suborder Mysticeti.
No morphological obstacles exclude this cetacean from mysticete lineage. Because of its lack of similarity
to cetaceans referred to the Odontoceti, and the presence of several critical archaeocete affinities which are
not retained on any known odontocete skull, this cetacean is referred to the suborder Archaeoceti.
